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OvmfPkg/IoMmuDxe: generalize IoMmuUnmap() to IoMmuUnmapWorker() 

IoMmuUnmapWorker() is identical to IoMmuUnmap(), it just takes an
additional BOOLEAN parameter called "MemoryMapLocked".  If the memory map
is locked, IoMmuUnmapWorker() does its usual job, but it purposely leaks
memory rather than freeing it. This makes it callable from
ExitBootServices() context.

Turn IoMmuUnmap() into a thin wrapper around IoMmuUnmapWorker() that
passes constant FALSE for "MemoryMapLocked".

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Brijesh Singh <brijesh.singh@amd.com>
Tested-by: Brijesh Singh <brijesh.singh@amd.com>
This commit is contained in:
Laszlo Ersek 2017-09-07 17:26:57 +02:00
parent 9ed745b967
commit 550acd08e5
1 changed files with 53 additions and 7 deletions
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60
OvmfPkg/IoMmuDxe/AmdSevIoMmu.c
View File

@ -318,8 +318,14 @@ Failed:
/**
Completes the Map() operation and releases any corresponding resources.
This is an internal worker function that only extends the Map() API with
the MemoryMapLocked parameter.
@param This The protocol instance pointer.
@param Mapping The mapping value returned from Map().
@param MemoryMapLocked The function is executing on the stack of
gBS->ExitBootServices(); changes to the UEFI
memory map are forbidden.
@retval EFI_SUCCESS The range was unmapped.
@retval EFI_INVALID_PARAMETER Mapping is not a value that was returned by
@ -327,11 +333,13 @@ Failed:
@retval EFI_DEVICE_ERROR The data was not committed to the target system
memory.
**/
STATIC
EFI_STATUS
EFIAPI
IoMmuUnmap (
IoMmuUnmapWorker (
IN EDKII_IOMMU_PROTOCOL *This,
IN VOID *Mapping
IN VOID *Mapping,
IN BOOLEAN MemoryMapLocked
)
{
MAP_INFO *MapInfo;
@ -339,7 +347,13 @@ IoMmuUnmap (
COMMON_BUFFER_HEADER *CommonBufferHeader;
VOID *EncryptionTarget;
DEBUG ((DEBUG_VERBOSE, "%a: Mapping=0x%p\n", __FUNCTION__, Mapping));
DEBUG ((
DEBUG_VERBOSE,
"%a: Mapping=0x%p MemoryMapLocked=%d\n",
__FUNCTION__,
Mapping,
MemoryMapLocked
));
if (Mapping == NULL) {
return EFI_INVALID_PARAMETER;
@ -412,7 +426,8 @@ IoMmuUnmap (
// original (now encrypted) location.
//
// For all other operations, fill the late bounce buffer (which existed as
// plaintext at some point) with zeros, and then release it.
// plaintext at some point) with zeros, and then release it (unless the UEFI
// memory map is locked).
//
if (MapInfo->Operation == EdkiiIoMmuOperationBusMasterCommonBuffer ||
MapInfo->Operation == EdkiiIoMmuOperationBusMasterCommonBuffer64) {
@ -426,18 +441,49 @@ IoMmuUnmap (
(VOID *)(UINTN)MapInfo->PlainTextAddress,
EFI_PAGES_TO_SIZE (MapInfo->NumberOfPages)
);
gBS->FreePages (MapInfo->PlainTextAddress, MapInfo->NumberOfPages);
if (!MemoryMapLocked) {
gBS->FreePages (MapInfo->PlainTextAddress, MapInfo->NumberOfPages);
}
}
//
// Forget and free the MAP_INFO structure.
// Forget the MAP_INFO structure, then free it (unless the UEFI memory map is
// locked).
//
RemoveEntryList (&MapInfo->Link);
FreePool (MapInfo);
if (!MemoryMapLocked) {
FreePool (MapInfo);
}
return EFI_SUCCESS;
}
/**
Completes the Map() operation and releases any corresponding resources.
@param This The protocol instance pointer.
@param Mapping The mapping value returned from Map().
@retval EFI_SUCCESS The range was unmapped.
@retval EFI_INVALID_PARAMETER Mapping is not a value that was returned by
Map().
@retval EFI_DEVICE_ERROR The data was not committed to the target system
memory.
**/
EFI_STATUS
EFIAPI
IoMmuUnmap (
IN EDKII_IOMMU_PROTOCOL *This,
IN VOID *Mapping
)
{
return IoMmuUnmapWorker (
This,
Mapping,
FALSE // MemoryMapLocked
);
}
/**
Allocates pages that are suitable for an OperationBusMasterCommonBuffer or
OperationBusMasterCommonBuffer64 mapping.